Single-chip semiconductor integrated circuit device and microcomputer

Abstract

A semiconductor integrated circuit device formed on a single chip or a microcomputer integrated on a semiconductor chip includes a central processing unit (CPU), an interface circuit (or an input/output port), a bus coupled to the CPU and the interface circuit (or the input/output port) and a variable logic circuit (or a subprocessor). The variable logic circuit (or the subprocessor) includes non-volatile memory elements storing instructions, a control circuit generating control signals in accordance with the stored instructions, and an arithmetic logic unit controlled by the generated control signals. Information can be written into the non-volatile memory elements from outside to construct the variable logic circuit or the subprocessor with any desired logical functions. The wiring operation of the memory elements can be executed in a short time, and a user can thus quickly obtain a single-chip microprocessor or a single-chip semiconductor integrated circuit device having hardware of peculiar prescribed specifications.